/*
This file is part of the OdinMS Maple Story Server
Copyright (C) 2008 ~ 2010 Patrick Huy <patrick.huy@frz.cc> 
Matthias Butz <matze@odinms.de>
Jan Christian Meyer <vimes@odinms.de>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License version 3
as published by the Free Software Foundation. You may not use, modify
or distribute this program under any other version of the
GNU Affero General Public License.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package tools;

import java.io.Serializable;
import java.util.*;

/**
 * Provides a strongly-typed map of keys to values.
 *
 * @param <K> The type of the keys.
 * @param <V> The type of the values.
 * @author Frz
 * @version 1.0
 * @since Revision 589
 */
public class ArrayMap<K, V> extends AbstractMap<K, V> implements Serializable {

  public static final long serialVersionUID = 9179541993413738569L;

  /**
   * Provides a strongly typed mapping of a key to a value.
   *
   * @param <K> The type of the key.
   * @param <V> The type of the value.
   * @author Frz
   * @version 1.0
   * @since Revision 589
   */
  public static class Entry<K, V> implements Map.Entry<K, V>, Serializable {

    public static final long serialVersionUID = 9179541993413738569L;
    protected K key;
    protected V value;

    /**
     * Class constructor
     *
     * @param key   Name of the key
     * @param value The value.
     */
    public Entry(K key, V value) {
      this.key = key;
      this.value = value;
    }

    /**
     * Gets the key.
     *
     * @return The key.
     */
    public K getKey() {
      return key;
    }

    /**
     * Gets the value.
     *
     * @return The value.
     */
    public V getValue() {
      return value;
    }

    /**
     * Sets a new value.
     *
     * @return The old value.
     */
    public V setValue(V newValue) {
      V oldValue = value;
      value = newValue;
      return oldValue;
    }

    /**
     * Compares two Entries for equality.
     *
     * @return <code>True</code> if the two Entries are equal,
     * <code>False</code> otherwise.
     */
    @Override
    public boolean equals(Object o) {
      if (!(o instanceof Map.Entry)) {
        return false;
      }
      @SuppressWarnings("rawtypes")
      Map.Entry e = (Map.Entry) o;
      return (key == null ? e.getKey() == null : key.equals(e.getKey())) &&
          (value == null ? e.getValue() == null : value.equals(e.getValue()));
    }

    /**
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
      int keyHash = (key == null ? 0 : key.hashCode());
      int valueHash = (value == null ? 0 : value.hashCode());
      return keyHash ^ valueHash;
    }

    /**
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
      return key + "=" + value;
    }
  }

  private transient Set<? extends java.util.Map.Entry<K, V>> entries = null;
  private ArrayList<Entry<K, V>> list;

  /**
   * Class constructor
   */
  public ArrayMap() {
    list = new ArrayList<Entry<K, V>>();
  }

  /**
   * Class constructor.
   *
   * @param map The <code>java.util.Map</code> containing keys and values to
   *            import.
   */
  public ArrayMap(Map<K, V> map) {
    list = new ArrayList<Entry<K, V>>();
    putAll(map);
  }

  /**
   * Class constructor.
   *
   * @param initialCapacity The initial size of the ArrayMap.
   */
  public ArrayMap(int initialCapacity) {
    list = new ArrayList<Entry<K, V>>(initialCapacity);
  }

  /**
   * Returns a set of entries in this ArrayList.
   *
   * @return The entries in a <code>java.util.Set</code> instance.
   */
  @Override
  @SuppressWarnings("unchecked")
  public Set<java.util.Map.Entry<K, V>> entrySet() {
    if (entries == null) {
      entries = new AbstractSet<Entry<K, V>>() {

        @Override
        public void clear() {
          throw new UnsupportedOperationException();
        }

        @Override
        public Iterator<Entry<K, V>> iterator() {
          return list.iterator();
        }

        @Override
        public int size() {
          return list.size();
        }
      };
    }
    return (Set<java.util.Map.Entry<K, V>>) entries;
  }

  /**
   * Puts a key/value pair into the ArrayMap.
   *
   * @param key   The key of <code>value</code>
   * @param value The value to insert into the ArrayMap.
   * @return <code>null</code> if no entry was replaced, the value replaced
   * otherwise.
   */
  @Override
  public V put(K key, V value) {
    int size = list.size();
    Entry<K, V> entry = null;
    int i;
    if (key == null) {
      for (i = 0; i < size; i++) {
        entry = (list.get(i));
        if (entry.getKey() == null) {
          break;
        }
      }
    } else {
      for (i = 0; i < size; i++) {
        entry = (list.get(i));
        if (key.equals(entry.getKey())) {
          break;
        }
      }
    }
    V oldValue = null;
    if (i < size) {
      oldValue = entry.getValue();
      entry.setValue(value);
    } else {
      list.add(new Entry<K, V>(key, value));
    }
    return oldValue;
  }
}
